The major objective of this project is to identify nonviable, chemically defined microbial components that are efficacious antitumour agents. The general approach in these studies is the development of standardized agents useful for both experimental and applied immunotherapy. The intent of this research is to 1) circumvent the use of infectious agents, 2) separate active components from potential antagonist substances, 3) remove or chemically modify components producing undesirable biological responses, and 4) develop and supply such efficacious preparations in stable and standardized forms.